1 #![feature(type_alias_impl_trait)]
3 // See https://github.com/rust-lang/rust/issues/87258#issuecomment-883293367
7 struct Struct<'b>(&'b ());
9 impl<'d> Trait1 for Struct<'d> {}
12 type FooFuture<'a>: Trait1;
13 fn foo<'a>() -> Self::FooFuture<'a>;
16 impl<'c, S: Trait2> Trait2 for &'c mut S {
17 type FooFuture<'a> = impl Trait1;
18 //~^ ERROR unconstrained opaque type
19 fn foo<'a>() -> Self::FooFuture<'a> {
20 Struct(unimplemented!())